Abstract: A system, apparatus, and method is provided to remotely measure atmospheric species using a long path differential absorption technique. In one embodiment, a source and a detector are collocated and at the far end of the absorption path a retro-reflector is mounted on a vehicle. The source generates an outgoing laser beam that is transmitted to the retro-reflector and reflected towards the detector as an incoming laser beam, and the detector receives the incoming laser beam that was reflected by the retro-reflector.

Abstract: A system, apparatus, and method is provided to remotely measure atmospheric species using a long path differential absorption technique. In one embodiment, a source and a detector are collocated and at the far end of the absorption path a retro-reflector is mounted on a vehicle. The source generates an outgoing laser beam that is transmitted to the retro-reflector and reflected towards the detector as an incoming laser beam, and the detector receives the incoming laser beam that was reflected by the retro-reflector.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: A fiber optical chemical detection system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using reversible colorimetric sensors that selectively form chemically reversible, intermolecular charge transfer-complexes with the gases that then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the contemporaneous extent and location of gas cloud concentration over the distributed wide area.

Abstract: In a laser assisted semiconductor etching process, a krypton fluoride excimer laser operating at 248 nm excites a carbonyl dichloride COCl.sub.2 radical precursor gas which decomposes into carbon monoxide and also atomic chlorine that bonds to laser illuminated surface layer materials of semiconductor devices to create gaseous chlorides which desorb to perfect selective etching, the surface layer material being Cu, Al, amphorous silicon, Ga.sub.(x) Al.sub.(1-x) As, CuIn.sub.(x) Ga.sub.(1-x) Se.sub.2, CdZnS, ZnO and other materials useful in the manufacture of semiconductor devices and solar cells.